Ace:Prototype Witness Publication

<img src="%ATTACHURLPATH%/WitnessPosting_web.gif" alt="WitnessPosting_web.gif" width="306" height="359" />

1. Once a week, the Post & Validate module builds an authentication tree from the CSI values generated during that week, using the same technique as before. The root value of the authentication tree concatenated with the witness from the previous week is fed into a hash function (currently SHA-256) to create the witness of the week. The proof of the authentication tree and the current time is written back to the CSI registry in the Proof field and the Time Frame ID, respectively.
2. The witness of the week currently gets posted to the newsgroups at Google, Yahoo and MSN. These newsgroup services will also automatically send emails to all the newsgroup subscribers with the witness value. In an operational setting, we expect these witness values to be published through widely known library or storage services. The witness is also saved on a CD-ROM.